Imagine a flock of birds, so thick its shadow blocks out the sun... so long it stretches from horizon to horizon... so vast, it takes three days to pass overhead. Now, imagine it gone. This is the story of the passenger pigeon—a bird that numbered in the billions, and now is but a shadow, a ghost, a haunting memory.

This poster exhibit was developed and designed by the University of Michigan Museum of Natural History, as a contribution to Project Passenger Pigeon, a year-long effort to commemorate the 100th anniversary of the extinction of this remarkable bird.